Fatal Acute Respiratory Distress Syndrome Research Articles

A Sequent of Gram-Negative Co-Infectome-Induced Acute Respiratory Distress Syndrome Are Potentially Subtle Aggravators Associated to the SARS-CoV-2 Evolution of Virulence.

Acute respiratory distress syndrome (ARDS) is one of the major problems in COVID-19 that is not well understood. ARDS is usually complicated by co-infections in hospitals. Although ARDS is inherited by Europeans and Africans, this is not clear for those from the Middle East. There are severe limitations in correlations made between COVID-19, ARDS, co-infectome, and patient demographics. We investigated 298 patients for associations of ARDS, coinfections, and patient demographics on COVID-19 patients' outcomes. Of the 149 patients examined for ARDS during COVID-19, 16 had an incidence with a higher case fatality rate (CFR) of 75.0% compared to those without ARDS (27.0%) (p value = 0.0001). The co-infectome association showed a CFR of 31.3% in co-infected patients; meanwhile, only 4.8% of those without co-infections (p value = 0.01) died. The major bacteria were Acinetobacter baumannii and Escherichia coli, either alone or in a mixed infection with Klebsiella pneumoniae. Kaplan-Meier survival analysis of COVID-19 patients with and without ARDS revealed a significant difference in the survival time of patients with ARDS (58.8 +/- 2.7 days) and without ARDS (41.9 +/- 1.8 days) (p value = 0.0002). These findings prove that increased hospital time was risky for co-infectome-induced SDRS later on. This also explained that while empiric therapy and lethal ventilations delayed the mortality in 75% of patients, they potentially did not help those without co-infection or ARDS who stayed for shorter times. In addition, the age of patients (n = 298) was significantly associated with ARDS (72.9 +/- 8.9) compared to those without it (56.2 +/- 15.1) and was irrespective of gender. However, there were no significant differences neither in the age of admitted patients before COVID-19 (58.5 +/- 15.3) and during COVID-19 (57.2 +/- 15.5) nor in the gender and COVID-19 fatality (p value 0.546). Thus, Gram-negative co-infectome potentially induced fatal ARDS, aggravating the COVID-19 outcome. These findings are important for the specific differential diagnosis of patients with and without ARDS and co-infections. Future vertical investigations on mechanisms of Gram-negative-induced ARDS are imperative since hypervirulent strains are rapidly circulating. This study was limited as it was a single-center study confined to Ha'il hospitals; a large-scale investigation in major national hospitals would gain more insights.

Bleomycin and perioperative care: a case report.

Bleomycin is associated with pulmonary toxicity ranging from pneumonitis, pulmonary fibrosis, to fatal acute respiratory distress syndrome. Oxygen administration can potentiate or precipitate bleomycin pulmonary toxicity, and the most common setting of oxygen exposure is during anesthesia. We report here the successful management and perioperative care of a patient with documented bleomycin pulmonary toxicity who had to undergo an eight hour long retroperitoneal surgery. With proper preoperative assessment, chest physiotherapy, inhaled steroids and bronchodilators, antibiotics, operative restriction of oxygen and fluids and good postoperative care no further pulmonary insult was inflicted.

Hemofiltration as an alternative for IL-6 inhibitors in COVID-19 cytokines storm associated with underlaying bacterial infections: A review Article.

SARS-CoV-2 causes mostly mild cases. However, a considerable number of patients develop fatal acute respiratory distress syndrome due to the cytokine storm and imbalanced immune response. Several therapies depending on immunomodulation have been used, including glucocorticoids and IL-6 blockers. However, their efficacy is not perfect with all patients and patients with concomitant bacterial infections and sepsis. Accordingly, studies on different immunomodulators, including extracorporeal techniques, are crucial to save this category of patients. In this review, we overviewed the different immunomodulation techniques shortly, with a brief review of extracorporeal methods.

Unraveling the Molecular and Cellular Pathogenesis of COVID-19-Associated Liver Injury.

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2) continues to cause substantial morbidity and mortality. Most infections are mild; however, some patients experience severe and potentially fatal systemic inflammation, tissue damage, cytokine storm, and acute respiratory distress syndrome. Patients with chronic liver disease have been frequently affected, experiencing high morbidity and mortality. In addition, elevated liver enzymes may be a risk factor for disease progression, even in the absence of underlying liver disease. While the respiratory tract is a primary target of SARS-CoV-2, it has become evident that COVID-19 is a multisystemic infectious disease. The hepatobiliary system might be influenced during COVID-19 infection, ranging from a mild elevation of aminotransferases to the development of autoimmune hepatitis and secondary sclerosing cholangitis. Furthermore, the virus can promote existing chronic liver diseases to liver failure and activate the autoimmune liver disease. Whether the direct cytopathic effects of the virus, host reaction, hypoxia, drugs, vaccination, or all these risk factors cause liver injury has not been clarified to a large extent in COVID-19. This review article discussed the molecular and cellular mechanisms involved in the pathogenesis of SARS-CoV-2 virus-associated liver injury and highlighted the emerging role of liver sinusoidal epithelial cells (LSECs) in virus-related liver damage.

Echocardiographic assessment of right ventricular dysfunction and outcome in patients with severe Covid-19 Pneumonia

ABSTRACT Background Fatal cardiovascular complications and acute respiratory distress syndrome (ARDS) account for the majority of SARS-CoV-2-associated deaths. The objective of this research was to find transthoracic echocardiography (TTE) of right ventricular (RV) dysfunction parameters that can be utilized to predict outcomes in individuals with severe COVID-19 pneumonia; Methods This observational research included 90 cases with severe COVID-19 pneumonia subjected to TTE on the day of admission and 3rd day to determine the relationship between severity, mortality in severe COVID-19 pneumonia and RV function parameters; Results TAPSE, SPAP, RVD, RV-WT, and RV-FAC had significant differences among the two groups. PaO2/FiO2 and average MAP were significantly correlated with all RV parameters. Adjusted multivariate regression analysis on day 1 showed that TAPSE and SPAP followed by RVFAC were significantly related to mortality. While on day 3, it was revealed that RVFAC then SPAP were significantly related to mortality. SPAP, with a cutoff point >46 mmHg, was the most sensitive parameter, while the most specific to predict mortality was TAPSE, with a cutoff point ≤15 mm. Conclusions In cases with severe COVID-19 pneumonia, prediction of mortality can be performed by measuring RV parameters by TTE with high sensitivity and specificity.

Carotenoids as potential inhibitors of TNFα in COVID-19 treatment.

Tumor necrosis factor-alpha (TNF-α) is a multifunctional pro-inflammatory cytokine, responsible for autoimmune and inflammatory disorders. In COVID-19 patients, increased TNF-α concentration may provoke inflammatory cascade and induce the initiation of cytokine storm that may result in fatal pneumonia and acute respiratory distress syndrome (ADRS). Hence, TNFα is assumed to be a promising drug target against cytokine storm in COVID-19 patients. In the present study, we focused on finding novel small molecules that can directly block TNF-α-hTNFR1 (human TNF receptor 1) interaction. In this regards, TNF-α-inhibiting capacity of natural carotenoids was investigated in terms of blocking TNF-α-hTNFR1 interaction in COVID-19 patients with the help of a combination of in silico approaches, based on virtual screening, molecular docking, and molecular dynamics (MD) simulation. A total of 125 carotenoids were selected out of 1204 natural molecules, based on their pharmacokinetics properties and they all met Lipinski's rule of five. Among them, Sorgomol, Strigol and Orobanchol had the most favorable ΔG with the best ADME (absorption, distribution, metabolism, excretion) properties, and were selected for MD simulation studies, which explored the complex stability and the impact of ligands on protein conformation. Our results showed that Sorgomol formed the most hydrogen bonds, resulting in the highest binding energy with lowest RMSD and RMSF, which made it the most appropriate candidate as TNF-α inhibitor. In conclusion, the present study could serve to expand possibilities to develop new therapeutic small molecules against TNF-α.

A brief review on the molecular biology of human adenoviruses

Human adenoviruses infection causes diseases worldwide in all age groups and genders, which is associated with a wide range of diseases affecting the gastrointestinal tract, respiratory tract, urinary tract, and the eye, but they are often isolated from the pharynx and stool of asymptomatic children. However, in developing countries, diarrhea is a major cause of morbidity and mortality; and after rotaviruses, human adenoviruses are considered to be the second most important cause of viral infantile diarrhea. Also, human adenoviruses cause fatal acute respiratory distress syndrome in healthy adults and are especially fatal in infants and immune-compromised individuals. This review summarizes both classical and contemporary discoveries in the study of human adenoviruses at the molecular level, with particular emphasis on viral receptors, capsid proteins, nucleic acid, and genome properties as well as the molecular interactions governing the virion assembly. In this article, we provide insightful information concerning the molecular aspects of human adenoviruses. This would develop an understanding of the virus and serve as a powerful tool in identifying new approaches for the prevention and treatment of adenoviral infection.

Fatal acute respiratory distress syndrome caused by blastomycosis after recent orthotopic liver transplantation in a non-endemic area

In blastomycosis, immunosuppression such as that following solid organ transplantation appears to be a risk factor for the development of overwhelming lung infection fulfilling criteria for the acute respiratory distress syndrome. Our transplant center, located outside traditional endemic areas for Blastomyces spp, experienced a case of fatal acute respiratory distress syndrome secondary to blastomycosis pneumonia in a recipient of recent orthotopic liver transplantation. The patient expired despite support with veno-venous extracorporeal membrane oxygenation.

Virofree, an Herbal Medicine-Based Formula, Interrupts the Viral Infection of Delta and Omicron Variants of SARS-CoV-2.

Coronavirus disease 2019 (COVID-19) remains a threat with the emergence of new variants, especially Delta and Omicron, without specific effective therapeutic drugs. The infection causes dysregulation of the immune system with a cytokine storm that eventually leads to fatal acute respiratory distress syndrome (ARDS) and further irreversible pulmonary fibrosis. Therefore, the promising way to inhibit infection is to disrupt the binding and fusion between the viral spike and the host ACE2 receptor. A transcriptome-based drug screening platform has been developed for COVID-19 to explore the possibility and potential of the long-established drugs or herbal medicines to reverse the unique genetic signature of COVID-19. In silico analysis showed that Virofree, an herbal medicine, reversed the genetic signature of COVID-19 and ARDS. Biochemical validations showed that Virofree could disrupt the binding of wild-type and Delta-variant spike proteins to ACE2 and its syncytial formation via cell-based pseudo-typed viral assays, as well as suppress binding between several variant recombinant spikes to ACE2, especially Delta and Omicron. Additionally, Virofree elevated miR-148b-5p levels, inhibited the main protease of SARS-CoV-2 (Mpro), and reduced LPS-induced TNF-α release. Virofree also prevented cellular iron accumulation leading to ferroptosis which occurs in SARS-CoV-2 patients. Furthermore, Virofree was able to reduce pulmonary fibrosis-related protein expression levels in vitro. In conclusion, Virofree was repurposed as a potential herbal medicine to combat COVID-19. This study highlights the inhibitory effect of Virofree on the entry of Delta and Omicron variants of SARS-CoV-2, which have not had any effective treatments during the emergence of the new variants spreading.

Radiation Induced Lung Injury (RILI) and COVID-19 Pneumonia: Are There Similarities by The Radiation Oncologist’s Point of View?

Coronavirus disease 2019 (COVID-19), is a novel infectious disease responsible for a severe acute respiratory syndrome due to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, which was firstly reported in January 2020 in Wuhan, Hubei Province, China, and then rapidly spread to other countries beyond China with a pandemic proportion in these last two years. In its severe lung expression, disease onset may result in death due to massive alveolar damage and progressive respiratory failure due to acute lung injury (ALI) which predisposes to fatal acute respiratory distress syndrome (ARDS). Autopsies reports describe a diffuse alveolar damage with vascular congestion, inflammatory cell population entrapped, thrombosis with hyaline membrane formation in the alveolar walls allowing to an irreversible lung destruction. Altogether these findings remind the radiation oncologists many similarities with radiation induced lung injury which is a well-known side effect of radiotherapy for lung cancer. A fascinating hypothesis is that a common inflammatory paradoxical response of lung could be underlying the injury whatever the causes may be, virus, drugs or ionizing radiation. In this paper we will review the similarities between these two illnesses just going through the mechanisms of ALI-ARDS and the role of the most important immune cells and cytokines involved.

Vasculopathy and Increased Vascular Congestion in Fatal COVID-19 and Acute Respiratory Distress Syndrome.

Rationale: The leading cause of death in coronavirus disease 2019 (COVID-19) is severe pneumonia, with many patients developing acute respiratory distress syndrome (ARDS) and diffuse alveolar damage (DAD). Whether DAD in fatal COVID-19 is distinct from other causes of DAD remains unknown. Objective: To compare lung parenchymal and vascular alterations between patients with fatal COVID-19 pneumonia and other DAD-causing etiologies using a multidimensional approach. Methods: This autopsy cohort consisted of consecutive patients with COVID-19 pneumonia (n = 20) and with respiratory failure and histologic DAD (n = 21; non-COVID-19 viral and nonviral etiologies). Premortem chest computed tomography (CT) scans were evaluated for vascular changes. Postmortem lung tissues were compared using histopathological and computational analyses. Machine-learning-derived morphometric analysis of the microvasculature was performed, with a random forest classifier quantifying vascular congestion (CVasc) in different microscopic compartments. Respiratory mechanics and gas-exchange parameters were evaluated longitudinally in patients with ARDS. Measurements and Main Results: In premortem CT, patients with COVID-19 showed more dilated vasculature when all lung segments were evaluated (P = 0.001) compared with controls with DAD. Histopathology revealed vasculopathic changes, including hemangiomatosis-like changes (P = 0.043), thromboemboli (P = 0.0038), pulmonary infarcts (P = 0.047), and perivascular inflammation (P < 0.001). Generalized estimating equations revealed significant regional differences in the lung microarchitecture among all DAD-causing entities. COVID-19 showed a larger overall CVasc range (P = 0.002). Alveolar-septal congestion was associated with a significantly shorter time to death from symptom onset (P = 0.03), length of hospital stay (P = 0.02), and increased ventilatory ratio [an estimate for pulmonary dead space fraction (Vd); p = 0.043] in all cases of ARDS. Conclusions: Severe COVID-19 pneumonia is characterized by significant vasculopathy and aberrant alveolar-septal congestion. Our findings also highlight the role that vascular alterations may play in Vd and clinical outcomes in ARDS in general.

Serum Levels of Chemokine Ligand-7 and Interferon-γ-induced Protein-10: Possible Severity and Prognostic Markers in Patients with COVID-19

Patients with coronavirus disease-19 (COVID-19) present as mildly, moderately, or severely and critically ill. Cytokine storm is responsible for fatal pneumonia and acute respiratory distress syndrome. Interferon-γ-induced protein-10 (IP-10) and chemokine ligand-7 (CCL-7) are chemokines that play a role in the chemotaxis of inflammatory cells and the release of pro-inflammatory cytokines. In this study, we assessed the serum levels of IP-10 and CCL-7 chemokines in COVID-19 patients and their correlation with disease severity and prognosis. The serum levels of CCL-7 and IP-10 were assessed in 67 COVID-19 patients and 10 healthy controls. Serum samples were collected and examined for these two markers using direct enzyme-linked immunosorbent assay. Patients were divided into two groups according to their disease severity. Serum levels of the test markers were compared between patients and controls, and between patients with different disease severities and correlated with other clinical and laboratory parameters. CCL-7 and IP-10 levels were significantly higher in patients than in controls and in severe than in mild/moderate cases. The receiver operating characteristic curve analysis of the two markers showed better performance of the combined markers as predictors of disease severity (area under the curve = 0.792). The results of our study suggest a potential role of IP-10 and CCL-7 as predictors of COVID-19 severity.

Review of Mesenteric Ischemia in COVID-19 Patients.

The new coronavirus (COVID-19) infection, first detected in Wuhan, China in 2019 has become a pandemic that has spread to nearly every country in the world. Through October 11, 2021, more than 23 billion confirmed cases and 4.8 million fatalities were reported globally. The bulk of individuals afflicted in India during the first wave were elderly persons. The second wave, however, resulted in more severe diseases and mortality in even younger age groups due to mutations in the wild virus. Symptoms may range from being asymptomatic to fatal acute respiratory distress syndrome (ARDS). In addition to respiratory symptoms, patients may present with gastrointestinal symptoms such as stomach pain, vomiting, loose stools, or mesenteric vein thrombosis. The frequency of patients presenting with thromboembolic symptoms has recently increased. According to certain studies, the prevalence of venous thromboembolism among hospitalized patients ranges from 9 to 25%. It was also shown that the incidence is significantly greater among critically sick patients, with a prevalence of 21–31%. Although the exact origin of thromboembolism is unknown, it is considered to be produced by several altered pathways that manifest as pulmonary embolism, myocardial infarction, stroke, limb gangrene, and acute mesenteric ischemia. Acute mesenteric ischemia (AMI) is becoming an increasingly prevalent cause of acute surgical abdomen in both intensive care unit (ICU) and emergency room (ER) patients. Mesenteric ischemia should be evaluated in situations with unexplained stomach discomfort. In suspected situations, appropriate imaging techniques and early intervention, either non-surgical or surgical, are necessary to avert mortality. The purpose of this article is to look at the data on acute mesenteric ischemia in people infected with COVID-19.

A Retrospective Observational Cohort Study on the Efficacy and Safety of Methylprednisolone Pulse Therapy for COVID-19 Pneumonia

Coronavirus disease 2019 (COVID-19) is associated with fatal acute respiratory distress syndrome, which can be ameliorated by methylprednisolone pulse therapy, thereby reducing the risk of progression to respiratory failure and death. We aimed to determine the efficacy and safety of methylprednisolone pulse therapy for patients with COVID-19 pneumonia. In this retrospective, observational cohort study, seventy patients (age, 35–91 years) who were admitted to Saitama Medical University Hospital in Japan between March 2020 and January 2021 due to COVID-19 pneumonia were included. The difference in mortality between the methylprednisolone pulse therapy (n = 22) and dexamethasone therapy (n = 48) groups was the primary outcome. Between-group differences in the average length of intensive care unit stay, duration of invasive mechanical ventilation, and incidence of treatment-related adverse events were the secondary outcomes. The methylprednisolone pulse therapy group showed a significantly lower mortality rate (3.8% vs. 20.2%, p = 0.006) and increased survival rate compared with the dexamethasone therapy group (p = 0.044). Additionally, without statistical significance, the average length of intensive care unit stay tended to be shorter in the methylprednisolone pulse therapy group (11.5 ± 6.1 days) than in the dexamethasone therapy group (22.3 ± 23.1 days) (p = 0.793). The average duration of invasive mechanical ventilation also tended to be shorter in the methylprednisolone pulse therapy group (15.3 ± 10.1 vs. 28.8 ± 9.2 days, p = 0.120). There were no significant differences in the incidence of treatment-related serious adverse events between the two groups. In conclusion, methylprednisolone pulse therapy for patients with COVID-19 pneumonia significantly reduced mortality and increased the survival rate compared to conventional dexamethasone therapy.

Diagnostic Challenges of Acute Eosinophilic Pneumonia Post Naltrexone Injection Presenting During The COVID-19 Pandemic

No abstract available. Article truncated after 150 words. Introduction Acute eosinophilic pneumonia (AEP) is a rare respiratory illness that may present with nonspecific symptoms ranging in severity from cough and dyspnea to potentially fatal acute respiratory distress syndrome. Although the exact etiology of AEP is unknown, it is thought to be a hypersensitivity reaction that can be idiopathic or caused by various infections, inhalation exposures, and medications (1). Here we present a rare case of AEP secondary to injectable naltrexone. Case Presentation A 45-year-old Caucasian male with a history of alcohol use disorder presented to the emergency room with a 3-day history of progressively worsening dyspnea and dry cough. The patient was a lifelong non-smoker with an unremarkable past medical history aside from alcohol abuse and obesity (BMI 41.64 kg/m²). He denied fever or chills, orthopnea, chest pain, or symptoms suggestive of paroxysmal nocturnal dyspnea. He also denied any recent sick contacts, including exposure to COVID-19. Relevant history …

Innate immunity: the first line of defense against SARS-CoV-2.

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus (SARS-CoV)-2, continues to cause substantial morbidity and mortality. While most infections are mild, some patients experience severe and potentially fatal systemic inflammation, tissue damage, cytokine storm and acute respiratory distress syndrome. The innate immune system acts as the first line of defense, sensing the virus through pattern recognition receptors and activating inflammatory pathways that promote viral clearance. Here, we discuss innate immune processes involved in SARS-CoV-2 recognition and the resultant inflammation. Improved understanding of how the innate immune system detects and responds to SARS-CoV-2 will help identify targeted therapeutic modalities that mitigate severe disease and improve patient outcomes.

Clinical phenotypes from fatal cases of acute respiratory distress syndrome caused by pneumonia

There have been no report of objective clinical characteristics or prognostic factors that predict fatal outcome of acute respiratory distress syndrome (ARDS) since the Berlin definition was published. The aim of this study is to identify clinically available predictors that distinguish between two phenotypes of fatal ARDS due to pneumonia. In total, 104 cases of Japanese patients with pneumonia-induced ARDS were extracted from our prospectively collected database. Fatal cases were divided into early (< 7 days after diagnosis) and late (≥ 7 days) death groups, and clinical variables and prognostic factors were statistically evaluated. Of the 50 patients who died within 180 days, 18 (36%) and 32 (64%) were in the early (median 2 days, IQR [1, 5]) and late (median 16 days, IQR [13, 29]) death groups, respectively. According to multivariate regression analyses, the APACHE II score (HR 1.25, 95%CI 1.12–1.39, p < 0.001) and the disseminated intravascular coagulation score (HR 1.54, 95%CI 1.15–2.04, p = 0.003) were independent prognostic factors for early death. In contrast, late death was associated with high-resolution computed tomography (HRCT) score indicating early fibroproliferation (HR 1.28, 95%CI 1.13–1.42, p < 0.001) as well as the disseminated intravascular coagulation score (HR 1.24, 95%CI 1.01–1.52, p = 0.039). The extent of fibroproliferation on HRCT, and the APACHE II scores along with coagulation abnormalities, should be considered for use in predictive enrichment and personalized medicine for patients with ARDS due to pneumonia.

When Immunity Kills: The Lessons of SARS-CoV-2 Outbreak.

Since its emergence at the end of 2019, SARS-CoV-2 has spread worldwide at a very rapid pace. While most infected individuals have an asymptomatic or mild disease, a minority, mainly the elderly, develop a severe disease that may lead to a fatal acute respiratory distress syndrome (ARDS). ARDS results from a highly inflammatory immunopathology process that includes systemic manifestations and massive alveolar damages that impair gas exchange. The present review summarizes our current knowledge in the rapidly evolving field of SARS-CoV-2 immunopathology, emphasizing the role of specific T cell responses. Indeed, accumulating evidence suggest that while T-cell response directed against SARS-CoV-2 likely plays a crucial role in virus clearance, it may also participate in the immunopathology process that leads to ARDS.

Molecular Insights into the Crosstalk Between Immune Inflammation Nexus and SARS-CoV-2 Virus.

COVID-19, a type of viral pneumonia caused by severe acute respiratory syndrome coronavirus 2 has challenged the world as global pandemic. It has marked the identification of third generation of extremely pathogenic zoonotic coronaviruses of twenty-first century posing threat to humans and mainly targeting the lower respiratory tract. In this review, we focused on not only the structure and virology of SARS-COV-2 but have discussed in detail the molecular immunopathogenesis of this novel virus highlighting its interaction with immune system and the role of compromised or dysregulated immune response towards disease severity. We attempted to correlate the crosstalk between unregulated inflammatory outcomes with disrupted host immunity which may play a potential role towards fatal acute respiratory distress syndrome that claims to be life-threatening in COVID-19. Exploration and investigation of molecular host-virus interactions will provide a better understanding on the mechanism of fatal COVID-19 infection and also enlighten the escape routes from the same.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00284-021-02657-9.

Binding of the Andes Virus Nucleocapsid Protein to RhoGDI Induces the Release and Activation of the Permeability Factor RhoA.

Andes virus (ANDV) nonlytically infects pulmonary microvascular endothelial cells (PMECs), causing acute pulmonary edema termed hantavirus pulmonary syndrome (HPS). In HPS patients, virtually every PMEC is infected; however, the mechanism by which ANDV induces vascular permeability and edema remains to be resolved. The ANDV nucleocapsid (N) protein activates the GTPase RhoA in primary human PMECs, causing VE-cadherin internalization from adherens junctions and PMEC permeability. We found that ANDV N protein failed to bind RhoA but coprecipitates RhoGDI (Rho GDP dissociation inhibitor), the primary RhoA repressor that normally sequesters RhoA in an inactive state. ANDV N protein selectively binds the RhoGDI C terminus (residues 69 to 204) but fails to form ternary complexes with RhoA or inhibit RhoA binding to the RhoGDI N terminus (residues 1 to 69). However, we found that ANDV N protein uniquely inhibits RhoA binding to an S34D phosphomimetic RhoGDI mutant. Hypoxia and vascular endothelial growth factor (VEGF) increase RhoA-induced PMEC permeability by directing protein kinase Cα (PKCα) phosphorylation of S34 on RhoGDI. Collectively, ANDV N protein alone activates RhoA by sequestering and reducing RhoGDI available to suppress RhoA. In response to hypoxia and VEGF-activated PKCα, ANDV N protein additionally directs the release of RhoA from S34-phosphorylated RhoGDI, synergistically activating RhoA and PMEC permeability. These findings reveal a fundamental edemagenic mechanism that permits ANDV to amplify PMEC permeability in hypoxic HPS patients. Our results rationalize therapeutically targeting PKCα and opposing protein kinase A (PKA) pathways that control RhoGDI phosphorylation as a means of resolving ANDV-induced capillary permeability, edema, and HPS. IMPORTANCE HPS-causing hantaviruses infect pulmonary endothelial cells (ECs), causing vascular leakage, pulmonary edema, and a 35% fatal acute respiratory distress syndrome (ARDS). Hantaviruses do not lyse or disrupt the endothelium but dysregulate normal EC barrier functions and increase hypoxia-directed permeability. Our findings reveal a novel underlying mechanism of EC permeability resulting from ANDV N protein binding to RhoGDI, a regulatory protein that normally maintains edemagenic RhoA in an inactive state and inhibits EC permeability. ANDV N sequesters RhoGDI and enhances the release of RhoA from S34-phosphorylated RhoGDI. These findings indicate that ANDV N induces the release of RhoA from PKC-phosphorylated RhoGDI, synergistically enhancing hypoxia-directed RhoA activation and PMEC permeability. Our data suggest inhibiting PKC and activating PKA phosphorylation of RhoGDI as mechanisms of inhibiting ANDV-directed EC permeability and therapeutically restricting edema in HPS patients. These findings may be broadly applicable to other causes of ARDS.